Planar Chiral [2.2]Paracyclophane-Based Thermally Activated Delayed Fluorescent Materials for Circularly Polarized Electroluminescence

Abstract

This work describes the construction of a novel planar chiral [2.2]paracyclophane-based thermally activated delayed fluorescence (TADF)active molecule with circularly polarized luminescence (CPL). The combination of the bulky planar chiral phenoxazinephane (PXZp) donor based [2.2]paracyclophane and triazine acceptor enables the highly efficient luminescence performances and excellent CPL properties. The enantiomers exhibit excellent TADF activities, the energy difference (ΔE ST ) between singlet and triplet of the molecule is only 0.03 eV. Notably, through solution-process, a yellow CP-OLEDs based on the molecule as the emitting layers displays high maximum brightness (L max ) up to 34 293 cd m −2 , maximum external quantum efficiency (EQE max ) up to 7.8% and remarkable CP-EL signal with g EL factor up to 4.6 × 10 −3 .

Frontiers in circularly polarized luminescence: molecular design, self-assembly, nanomaterials, and applications

“…to prepare CPL-active polymers [4,64,65], metal-organic frameworks (MOFs) [66], and thermally-activated delayed fluorescence (TADF) [67] materials, which will be further discussed in the following sections (Sections 2.5, 2.6, and 3.2).…”

“…In 2015 and 2017, Di Bari et al [175,297] blended the ionic europium complex CsEu(hfbc) 4 ( 70 . At the same time, some groups also fabricated the CP-OLEDs with a single layer based on small fluorescence and TADF molecules with similar properties [67,169,[300][301][302][303].…”

Electron-withdrawing Group Modified Carbazolophane Donors for Deep Blue Thermally Activated Delayed Fluorescence OLEDs

“…The OLED showed an EQE max of 7.8% and CIE coordinates of (0.49, 0.50). 19 As we can see from Fig. 1 since our first report, a handful of emitters have been reported containing the PCP moiety; however none to date show pure blue emission.…”

Electron-withdrawing group modified carbazolophane donors for deep blue thermally activated delayed fluorescence OLEDs

“…The OLED showed an EQE max of 7.8% and CIE coordinates of (0.49, 0.50). 19 As we can see from Figure 1 since our first report, a handful 4 of emitters have been reported containing the PCP moiety; however none to date show pure blue emission.…”